Dang, that was a lot of replies over night. Interesting stuff. Its funny that only 1 person used the reason which I thought a lot would give, "they look cool".
I guess on the fact of it, that reason is pretty shallow, but I still thought it would be common. I've still got my first tree, turned it in to 2 trees. One of them is a 9ft tree in the ground, the other is almost exactly the same as when I airlayered it, 4 years ago. Goes to show what ground growing does, and lack of work on a tree. The ground grown material will be good one day, and I'll have one of those mallsai to greatness, progressions.
People seem to turn to Bonsai when times are tougher for them, whether they were already in the hobby or not. Do you never find anything holds you back from doing Bonsai? Fear of mistakes?